1. Field of the Invention
The present invention relates to a method of manufacturing an optical sensor module including an optical waveguide section and a substrate section with an optical element mounted therein, and to an optical sensor module obtained thereby.
2. Description of the Related Art
As shown in FIGS. 13A and 13B, an optical sensor module is manufactured by: individually producing an optical waveguide section W0 in which an under cladding layer 71, a core 72 and an over cladding layer 73 are disposed in the order named, a substrate section E0 in which an optical element 82 is mounted on a substrate 81; and then connecting the above-mentioned substrate section E0 to an end portion of the above-mentioned optical waveguide section W0, with the core 72 of the above-mentioned optical waveguide section W0 and the optical element 82 of the substrate section E0 kept in alignment with each other. In FIGS. 13A and 13B, the reference numeral 74 designates an adhesive layer, 75 designates a base, 83 designates an insulation layer, 84 designates an optical element mounting pad, and 85 designates a transparent resin layer.
The above-mentioned alignment between the core 72 of the above-mentioned optical waveguide section W0 and the optical element 82 of the substrate section E0 is generally performed by using a self-aligning machine (see, for example, Japanese Published Patent Application No. 5-196831). In this self-aligning machine, the alignment is performed with the optical waveguide section W0 fixed on a fixed stage (not shown) and the substrate section E0 fixed on a movable stage (not shown). Specifically, when the above-mentioned optical element 82 is a light-emitting element, the alignment is as follows. As shown in FIG. 13A, while the position of the light-emitting element is changed relative to a first end surface (light entrance) 72a of the core 72, with light H1 emitted from the light-emitting element, the amount of light emitted outwardly from a second end surface (light exit) 72b of the core 72 through a lens portion 73b provided in a second end portion of the over cladding layer 73 (the photovoltaic voltage developed across a light-receiving element 91 provided in the self-aligning machine) is monitored. Then, the position in which the amount of light is maximum is determined as an alignment position (a position in which the core 72 and the optical element 82 are appropriate relative to each other). On the other hand, when the above-mentioned optical element 82 is a light-receiving element, the alignment is as follows. As shown in FIG. 13B, the second end surface 72b of the core 72 receives a constant amount of light (light emitted from a light-emitting element 92 provided in the self-aligning machine and transmitted through the lens portion 73b provided in the first end portion of the over cladding layer 73) H2. While the position of the light-receiving element is changed relative to the first end surface 72a of the core 72, with the light H2 emitted outwardly from the first end surface 72a of the core 72 through a second end portion 73a of the over cladding layer 73, the amount of light received by the light-receiving element (the photovoltaic voltage) is monitored. Then, the position in which the amount of light is maximum is determined as the alignment position.
However, while the alignment using the above-mentioned self-aligning machine can be high-precision alignment, it requires labor and time and therefore unsuited for mass production.